EXPLOITATION OF A PREFERENTIALLY TRANSMITTED CHROMOSOME FROM AEGILOPS-SHARONENSIS FOR THE ELIMINATION OF SEGREGATION FOR HEIGHT IN SEMIDWARF BREAD WHEAT-VARIETIES

Certain semidwarf bread wheat varieties tend to lose chromosome 4D, carrying the dwarfing gene Rht2, resulting in the production of tall "offtypes." To overcome this problem translocations have been isolated involving the arm of the Aegilops sharonensis chromosome 4S1 that carries the genes determining preferential transmission and the Rht2-carrying arm of chromosome 4D of Triticum aestivum. These translocations, which were derived by self-pollinating plants doubly monosomic for chromosomes 4D and 4S1, appear to be preferentially transmitted in both pollen and egg, thus ensuring constant disomy and homozygosity of Rht2.